http://www.bbc.co.uk/programmes/b07g9z87When viewed in the infra-red (not the near infra-red but the infra-red proper) by the Liverpool Telescope on the island of La Palma, the companion galaxy with the Whirlpool Galaxy is clearly older.http://www.bbc.co.uk/iplayer/episode/b0 ... ool-galaxyStarting at 15 minutes 45 seconds in. Where they present a special photo of the galaxy taken for The Sky at Night by the telescope on 31 May - the companion galaxy glows blue and the main galaxy glows red. The companion galaxy is full of old stars, whereas the main galaxy has young and cooler stars (and more dust and gas and less hot stars) and suspected active star formation currently underway in the long-term.